Shedding mechanism for looms



Oct. 20; 1936. I H. H. BURDETT 2,053,129

SHEDDING MECHANISM FOR LOOMS Filed March 10, 1936 2 Sheets- Sheet 1 W/7Wf55. INVENTOR.

a flee/{65H 5 1205??? Cu/vro/vd. WM

I ATTORNEY.

Oct. 20, 1936. H. H. BURDETT SHEDDING MECHANISM FOR LOOMS Fi led March 10, 1936 2 Sheets-Sheet 2 l3 Zz 1'1 3. W/T/VEJS.

' INVENTORJ fibEME/fi 51/605777 5 ATTORNEY.

Patented Oct. 20, 1936 UNITED STATES 2,058,129 SHEDDING MECHANISM FOR LOOMS Horace H. Burdett Hopedale, Mass., assignor to Draper Corporation, Hopedale, Mass at corporation of Maine Application March 10, 1936, Serial No. 68,085

4 Claims.

The present invention pertains to looms, and has more particular reference to harness operating mechanism therefor of the cam-and-treadle type.

Looms of the type mentioned are commonly provided with a plurality of substantially vertical harness frames which are moved up and down, to form the shed opening, by means of cams and treadles positioned beneath the harness frames. Where the cloth being woven is'of other than a plain weave, so-called, the harness cams are fixed to an auxiliary shaft which is' driven from the well known main cam shaft of the loom. The main cam shaft revolves at the rate of one revolution to'eachtwo picks of the loom, which is the speed ratio required for the harness cams in a loom producing cloth'of a plain weave. Accordingly, it is common practice to fix the harness cams, for a plain weave, to the main cam shaft wherever practicable, thus eliminating the auxiliaryshaft and its supporting and driving parts.

The harness cams are fixed to the main cam shaft, as aforesaid, in a considerable proportion of the looms in actual operation. There are, however, many looms producing cloth of a plain weave wherein it has heretofore been considered impossible to fix the harness cams to the main cam shaft. Looms of the latter class are those wherein, "for certain reasons not herein enumerated, the main cam shaft is positioned so close to the vertical planes of the harness frames that harness cams of the required size fixed to the cam shaft would project forwardly into the said planes, thus interfering with the jack straps.

It is principally to looms of the last-mentioned class that my invention pertains, and I propose to provide therein a harness operating mechanism which shall permit the fixing of the harness cams to the main cam .shaft,thus eliminating the above-mentioned auxiliary shaft parts.

Thepreferred embodiment of the invention, as herein disclosed in detail, comprises a loom having substantially vertical harness frames and a main cam shaft positioned close to the planes of the harness frames as above described, harness cams fixed to the main cam shaft, treadles positioned beneath the cams, and connecting members for operating the harness frames from their respective treadles. The connecting members are comprised of bifurcated metal bodies the legs of which pass on opposite sides of the harness cams so as not to interfere with the latter, as hereinafter described.

The said preferred embodiment is illustrated on the accompanying drawings, of which:

Fig. 1 is a view partly in section and partly in front elevation of a loom to which the said preferred embodiment of the invention has been applied;

. Fig. 2 is a view of the same in cross-section; Fig. 3 is a detail view of part of the connecting member;

Fig. 4 is aview in elevation of certain mechanism appearing on Fig. 2; and

Fig.5 is a view in cross-section taken approximately on line 5-5, Fig. 3.

The loom shown on the drawings is of conventional construction, except. forthe harness operating mechanism, most of the conventional mechanisms and parts being omitted as they form no part of the present invention. There is shown, however, a part of the loom frame which is comprised of loom sides, as I, connected by cross members 2 and supporting an arch 3. A main cam shaft is supported in bearings on the loom frame and extends widthwise of the loom. The cam shaft 4 is rotated at a speed of one complete revolution for each two complete picks or cycles of the loom, as is customary in all, or at least substantially all looms.

Front and rear harness frames 5 and 6,'resp'e'citively, are positioned in parallel substantially vertical planes which extend widthwise of the loom, It may be here noted that'the front of the loom is toward the right, Figs. 2 and 4. The actual number of harness frames employed is not important, but it is essential that each harness frame move alternately up and down to form a plain weave. The harness frames are, of course, moved substantially vertically. 'rne harness frames may be moved up by any suitable usual means, there being shown on Fig. l, by way of example, the well-known roll-and-shaft top motion I which moves one harness frame up as the other one moves down.

The cam shaft 4 is positioned below the harness frames and to the rear of the planes thereof. In common with other looms of the type involved, the cam shaft is placed so close to the planes of the harness frames that, if harness camsof the size required to produce a proper shed opening S are fixed on the cam shaft, such cams in revolving will intersect the planes of the harness frames. It is this condition which has given rise to the prior practice of positioning the harness cams on an auxiliary shaft which may be positioned the requireddistance rearwardly of the main cam shaft. The drawings do not show such an aux-- iliary shaft because with the present invention none is required.

In accordance with the present invention, harness cams 8 and 9 are fixed directly to the main cam shaft 4, the cams in revolving intersecting or passing through the planes of the harness frames as above mentioned. The drawings show but two harness cams, there being for this wide loom a duplicate set of harness cams and operating parts at the other or right hand side of the center of the loom. The harness opcrating mechanism of the present invention is designed so as to permit the use of these cams fixed to the main cam shaft.

The particular embodiment of harness operating mechanism shown includes harness treadles I0 and I I which are pivoted at their rearward end.

as at I2 and extend forwardly beneath the harness cams. These treadles extend generally horizontally, substantially normal to the planes of the harness frames, except that they are reciprocated up and down. The forward ends of the treadles project through the planes of the harness frames and are notched on their under sides as shown at I3. The treadles are provided intermediate their ends with cam follower means such as rolls I4, I4. The cam 8 operates the treadle I0 and the cam 9 operates the treadle II, the movement being communicated to the harness frames 5 and 6 by connecting members I5, I5.

The connecting members I5, I5 are identical in every respect. Consequently, only the front member Will be described in detail. The connecting member, or connector, is comprised of a rigid metal body, preferably of cast iron, which is bifurcated to provide side members or legs I6, I6. The legs I6 extend substantially vertically and are spaced apart in the direction of the width of the loom, that is, in a direction parallel to the cam shaft 4. The spacing is such as to permit the harness cam to pass between the legs of the connector as clearly shown. Any suitable means may be provided for connecting the upper end of the member I5 to a harness frame. As shown, the upper end of the member is apertured to receive a conventional jack stick I! which is suspended from the lower bar of the harness frame by means of hooks and eye members indicated generally by numeral I8.

The legs I6 of the connector extend on opposite sides of the cam and treadle. The lower ends of the legs are connected by a yoke portion I9 formed integrally therewith beneath the forward end of the treadle. A cross-bar 20 is supported by the connector for vertical sliding movement. The cross-bar may be so supported by means of guide fins 2|, 2| which extend upwardly from the yoke I9 and engage in grooves formed in the ends of the cross-bar as shown more clearly on Fig. 5. The cross-bar is adjustable vertically by means of an adjusting screw 22 which is threaded into the yoke and bears upwardly against the cross-bar. The cross-bar engages in an appropriate notch I3. The cross-bar thus constitutes means for connecting the lower end of the member I5 with the forward end of the treadle, wherefore adjustment of the cross-bar serves to adjust the effective length of the connecting member.

It will be apparent that the construction above described, by providing for the positioning of the harness cams on the main cam shaft, entirely eliminates a considerable number of parts heretofore considered necessary on this type of loom. Furthermore, the construction is simple, inexpensive and quite substantial, but still very easy to adjust. I do not, however, consider that the invention is limited to the exact construction shown.

Having fully disclosed the preferred embodiment of the invention, I claim:

1. In a loom, the combination of the usual substantially vertically positioned harness frame and the usual main cam shaft positioned below and rearwardly of the harness frame, with a harness cam fixed to said cam shaft, the size of said cam and the distance between the cam shaft and the plane of the harness frame being such that the cam in revolving intersects said plane, a treadle pivoted at its rearward end and extending forwardly beneath said cam, cam follower means on said treadle whereby the latter is operated by said cam, a bifurcated metal connecting member positioned in the plane of said harness frame, the legs of said member passing on opposite sides of said cam, means connecting the lower end of said member directly to the forward end of said treadle, and means conmeeting the upper end of said member to said harness frame.

2. In a loom, the combination of the usual substantially Vertically positioned harness frame and the usual main cam shaft positioned below and rearwardly of the harness frame, with a harness cam fixed to said cam shaft, the size of said cam and the distance between the cam shaft and the plane of the harness frame being such that the cam in revolving intersects said plane, a treadle pivoted at its rearward end and extending forwardly beneath said cam, cam follower means on said treadle whereby the latter is operated by said cam, a bifurcated metal connecting member positioned in the plane of said harness frame, the legs of said member passing on opposite sides of said cam and treadle, a vertically adjustable cross-bar carried by the lower end of said member and engaged beneath the forward end of said treadle, and means connecting the upper end of said member to said harness frame.

3. In a loom harness operating mechanism, the combination of the main cam shaft, a harness cam fixed to said shaft, a notched treadle operated by said cam, and a jack stick, with a rigid metal connector secured at its upper end to said jack stick, said connector having substantially vertical legs which are spaced apart in a direction parallel to said cam shaft to permit said cam to pass therebetween, said connector having an integral yoke connecting the lower ends of said legs, a vertically slidable cross-bar guided by the legs of said yoke and engaging in a notch in said treadle, and an adjusting screw carried by said yoke and acting upwardly against said cross-bar.

4. In a loom harness operating mechanism, the combination of the usual horizontally extending harness jack with a notched harness treadle extending substantially normal to the vertical plane containing said jack, and a device for connecting said treadle with said jack; said device consisting of a metal body having side members which are spaced apart in the direction of the length of said jack to permit a harness cam to pass therebetween, means securing the upper end of said body to said jack, a yoke integrally connecting said side members at the lower end thereof, said members having guide fins extending upwardly from said yoke, a crossbar engaging in a notch in said treadle, said cross-bar having grooves in its ends by which it is slidably mounted on said fins, and means carried by said yoke for vertically moving said cross-bar along said fins to thereby adjust the effective length of said device.

HORACE H. BURDE'I'I.

CJI 

